Knob retaining device



A ril 14, 1953 T. F. NELSON KNOB RETAINING DEVICE Filed Jan. 25, 1951 1 enbor:

Tho s E Nelson,

His Attorney.

zandrhas as :amimpoflantpbiect h m Patented Apr. 14, 1953 UNITED sures OFFICE KNOB IRETAINING mines New York gp jf, Ngl son, Stratfglr i 4. 91. QSSJEBPI L ene a iE egt l c Seminar a cor ora io o .965 :pf improved means -;for holding a knob-like member inia predetermined .positionon h t.-

.A further ;object ;of Joly jnve;

andconstruction. abeingimorei asi y andzeponamial yre fected han ipllelbiflil new-ices. such as s screws en aging threaded ho es 511: :a shaf an -=member to beretained hereto.

.Azfurther object of mminyentnn is to prov d ia' etainin nevice which affords slida l a. ne mentnf the z positiqn of .a memh ae ain diune vid .a shear safety r eric greater :than a kg venril il fi li. mittedirorna membe n mentzthereof, a kno is: eld ina Astillfurtherpbiechofmy v n throne heme therefrom-in aplane substantially at right aiigles to the p an io h sn e in r ion- 'iIh e tionsare terminated in end sections bent hack toward'the center portionto'jlieat an acnteangle withgrespect to theleg portions. The leg portions-uare forced'into slots inth-eilgnob soLthat the center portion of the spring clip is in "frictional engagement with the shaft.

While my invention will be described as applied to retaining a knob on a shaft, it is to be understood that it is not limited to such application, as the disclosure in this respect is merely illustrative for purposes of explaining the inventive concept.

The features of my invention which I believe to be novel are set forth with particularity in the appended claim. My invention itself, however, both as to its organization and method of operation together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawing, in which Fig. l is a perspective view of a preferred form of the spring clip of my invention; Fig. 2 is an end view of a knob, spring clip, and shaft, which is shown in section, constructed and held together in accordance with one embodiment of my invention; Fig. 3 is the same as Fig. 2 except that it illustrates a second embodiment of my invention; Fig. 4 is the same as Fig. 2 except that it illustrates a third embodiment of my invention; and Fig. 5 is a sectional side view of Fig. 4

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I2 a ong ne 5.1. i lustr tin the en a imeht. some t .2, .3 and of th s in 4113s .With the gkn h seein ,the .snawms. a spr ng clip I is nrbtid d t .psil s l e iion In wh ch is preferabl thesha eo' .Q a t unc te V a i also with two leg portions Ib and to, extend- .in a plan ubstantiall a rig an les to the lane o the c n e po on 1a,. an ..t. :m men by two .9 d s c io s i an is which a bent toward nte no t n lg o l e a a we an le w th-res e to o tion 1b and 1c respe e tr C i .1 sed to ho d a member an ass kn b '.in. predetermin posit on .0 shaft means uch as .gyli, ca haft .3 K 10. isbmtided with a eces !shap d-subtially to con o m .59 th sha .o the sha .s to r cet .an alw n tivoan horine reeases. such the ,re 'tansi a .r' es e 5 and :5 dis o e -ono posit s de f rsc ssfi fo rece ing th ee mama .o the .I [a .shQWn i Fi 'lhe w dih Q ;rsses. andfimushbesuc :thfi'whenthe-leg o tions andl o sli 1' are in ert d t ere n; and seot o s ldand .11 ar de- ;r .ed slightly; ther b a sing sec io d an it itaex rt,nressureqnthe sides v rec ss s fen 4 Imma eria o whic .t sp irie .Ql p I i ;fo me. -sh. 1 besom what harde than th materia from whic jkno 'lis fo m d s tha during an attempted withdrawal of clip -I from its engagement in anchoring recesses 5 and 6, end sections Id and I6 of the leg portions dig into the side of their respective anchoring recesses, tending to prevent Withdrawal therefrom.

After the leg portions Ib and to of the clip 5 have been inserted in recesses 5 and 6, the center portion Ia lies partially over the entrance to recess 4 in knob 2. Thus, when shaft 3 is inserted into recess 4, center portion Ia is forced to the side of the entrance whereby leg portions Ib and I0 are moved toward end sections Id and I6 and a spring pressure is exerted on the shaft 3 by portion Ia and on the sides of recesses 5 and 6 by sections Id and I e.

In Fig. 2 the cylindrical surface of shaft 3 is unaltered so that the knob 2 is retained on the shaft 3 by frictional forces between the cylindrical surface of shaft 3 and portion la of the clip I. The maximum force against which knob 2 is retained on shaft 3 may be determined by the design of spring clip I and the degree of roughness given to the surface of shaft 3. Therefore, this embodiment of the invention is of particular value to retain a knob on a shaft against relatively small axial and circumferential forces but at the same time allowing the knob to be slidably and rotatably adjusted in position relative to the shaft by slightly greater forces.

In Fig. 3, the shaft 3 is provided with two notches 'l and 1' in its surface, these notches being formed with substantially the same angle between them as the angle 'of the V in spring clip I. Notches l and 1' may be of any width along the axis of shaft 3 greater than the diameter of the wire forming spring clip I. Thus, if notches l and l are only slightly greater in width along the axis of shaft 3 than the diameter of the wire forming spring clip I, center portion la fits snugly into notches I and l, andthe knob is firmly retained on the shaft against axial and circumferential forces. This is probably the most useful form of the embodiment shown in Fig. 3.

However, if notches hand i in Fig. 3 are made of greater width and extended along the axis of the shaft 3, the knob 2 will be firmlyretained on the shaft 3 against circumferential forces but will be semi-firmly retained against axial forces, as in the embodiment of Fig. 2, whereby the knob 2 may be slidably adjusted to any axial position along the shaft within the axial limits of notches l and 1'.

Further, the circumferential frictional retaining force between spring and shaft in the embodiment of Fig. 3 may be determined by the design of the spring clip I, the angle between device, limiting the maximum torque transmittable between knob 2 and shaft 3. If the circumferential force between the knob 2 and shaft 3 exceeds the designed circumferential frictional force, the knob will slip upon the shaft until such time that the two forces equalize, when the knob 2 will re-index at the same circumferential position on the shaft 3 and transmit the torque.

In Figs. 4 and 5 the shaft 3 is provided with an annular groove 8 into which the center portion la of the clip I fits under spring force so that the knob 2 is firmly retained upon the shaft 3 against axial forces but only semi-firmly against circumferential forces depending upon the design of the spring and the roughness of the surface of groove 8. Thus, the embodiment shown by Figs. 4 and 5 is most useful when used on a shaft to be moved or pulled axially but which must not be loaded by too great of a circumferential torque.

While the present invention has been described by reference to particular embodiments thereof, it will be understood that numerous modifications may be made by those skilled in the art without actually departing from the invention. I, therefore, aim in the appended claim to cover all such equivalent variations as come within the true spirit and scope of the foregoing disclosure.

What I claim as new and desire to secure by Letters Patent of the United States is:

A retaining and indexing device comprising a cylindri'calshaft having two notches in the periphery thereof extending circumferentially of the shaft, a knob having a cylindrical recess therein for receiving said shaft and having two anchoring recesses on opposite sides of said first mentioned recess, a spring wire clip having a v-shaped center portion, two leg portions extending from said center portion in planes substantially at right angles to the plane of said center portion, two end sections terminating said leg portions and each bent toward said center portion to lie at an acute angle with respect to its respective leg portion, said notches being located with respect to one another at an angle normal to the axis of the shaft substantially equal to the angle formed by said V-shaped center portion of said spring clip, said clip positioned with said leg portions thereof each disposed in a different one of said anchoring recesses and with said end section of each leg portion in frictional engagement with the side of its respective anchoring recess, said V-shaped portion'of said spring engaging said shaft in said notches to retain said knob in a predetermined indexed position with respect to said shaft.

THOMAS F. NELSON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,172,977 Kimball Sept. 12, 1939 2,180,929 Murphy Nov. 21, 1939 2,271,266 Kost Jan. 27, 1942 

